1. Field of the Invention
This invention relates to a permanent vault for disposing of containers particularly containers which are filled with chemical hazardous waste materials.
2. Description of the Prior Art
Modern industry creates huge quantities of waste materials which include nuclear waste materials, biodegradable waste materials, municipal wastes and hazardous chemical wastes. The disposition of hazardous chemical wastes is a source of great concern to environmentalsts because of the tendency of such chemical hazardous waste materials to leach into the natural water supply and thereby to contaminate drinking water. Many of the past practices for disposing of such hazardous chemical waste materials are unacceptable today. There are hundreds of isolated landfills where waste disposers have merely dumped the hazardous chemical waste materials into open pits, into mineshafts, into public streams, etc.
Frequently, chemical hazardous waste materials are accumulated by the waste generators in fiber or metal drums which are stored at the premises of the waste generator until a sufficient quantity is accumulated to warrant removal from the premises and disposal by a waste disposal operator. It has been a past practice, unacceptable today, to dump the complete containers into landfills.
A more acceptable procedure for such materials is described in U.S. Pat. No. 4,166,709 where a waste disposal basin is provided above the existing high water table level in the region of the disposal site. The basin is lined with a water-impervious basin liner and an encapsulation is prepared from a water-impermeable layer of material and a further water-impervious layer of material. The chemical hazardous waste materials are deposited above the water-impervious layer of material until the permanent vault is filled to the satisfaction of the disposal site operator. Thereafter a covering water-impervious layer is applied and a further water-impermeable layer of material is applied forming a double encapsulation around the chemical hazardous waste materials. Thereafter the permanent vault is covered with indigenous earth materials, further covered with a water-impervious layer of materials to preclude entry of surface water into the vault and thereafter the region is covered with topsoil and revegetated.
While this foregoing permanent encapsulation vault is environmentally acceptable, the use of such vaults for confining containerized chemical hazardous waste materials presents some anticipated difficulties as the containers may deteriorate from corrosion and collapse. Such deterioration may create void spaces within the encapsulation vault which may result in geological weaknesses in the structure permitting the development of structural cracks or other openings in the double encapsulation of the vault. The vaults are provided with permanent monitoring installations to provide prompt observation of the occurrence of such faults and to permit the disposal site operator to take corrective measures before the confined chemical waste materials can create environmental damage.